syzbot

==================================================================
BUG: KCSAN: data-race in generic_file_direct_write / generic_file_read_iter

write to 0xffff888107e93470 of 8 bytes by task 26618 on cpu 0:
 i_size_write include/linux/fs.h:932 [inline]
 generic_file_direct_write+0x19d/0x1f0 mm/filemap.c:3870
 __generic_file_write_iter+0xae/0x120 mm/filemap.c:3999
 generic_file_write_iter+0x7d/0x1c0 mm/filemap.c:4039
 do_iter_write+0x4ad/0x770 fs/read_write.c:860
 vfs_iter_write+0x56/0x70 fs/read_write.c:901
 iter_file_splice_write+0x462/0x7e0 fs/splice.c:736
 do_splice_from fs/splice.c:933 [inline]
 direct_splice_actor+0x8a/0xb0 fs/splice.c:1142
 splice_direct_to_actor+0x31d/0x690 fs/splice.c:1088
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888107e93470 of 8 bytes by task 26627 on cpu 1:
 i_size_read include/linux/fs.h:910 [inline]
 generic_file_read_iter+0x2f4/0x330 mm/filemap.c:2768
 call_read_iter include/linux/fs.h:2014 [inline]
 copy_splice_read+0x26b/0x4b0 fs/splice.c:364
 vfs_splice_read fs/splice.c:992 [inline]
 splice_direct_to_actor+0x2aa/0x690 fs/splice.c:1069
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000032a00 -> 0x0000000000032c00

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26627 Comm: syz-executor.2 Not tainted 6.7.0-rc5-syzkaller-00125-gc7402612e2e6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================